1. Technical Field
The present invention relates to a driving force control unit for a vehicle which selects one driving force characteristic from a plurality of different driving force characteristics by manipulation (outside operation) and determines driving force based on the selected driving force characteristic.
2. Related Art
Conventionally, in an engine with a so-called electronically controlled throttle in which a throttle valve is electronically controlled using a throttle actuator, an accelerator pedal and the throttle valve are not mechanically linked and hence, opening of the throttle valve (throttle opening) can be controlled with nonlinear characteristic with respect to an operation amount of the accelerator pedal (accelerator opening).
For example, publication of unexamined patent application JP A 2005-188384 discloses a technology in which an operation state of an engine is divided into a plurality of operation regions based on an engine rotational speed and accelerator opening and a map is set for each operation region to perform control of the throttle valve conforming to the operation state of the engine.
According to the technology disclosed in this reference, excellent driving performance is obtained by increasing potential to the maximum at the time of high-speed running, and driving with reduced power is attained when stopping and running are repeated in such cases as traffic congestion. Thus, excellent drivability can be achieved.
According to the technology shown in the above reference, the driving force characteristic is changed according to the accelerator pedal operation even if the vehicle travels reverse direction.
However, in the reverse traveling, a driver drives the vehicle based on a delicate accelerator pedal manipulation and steering manipulation with improperly attitude by paying attention around the vehicle. For this reason, if the driving range is changed according to the accelerator pedal operation, the accelerator pedal feeling is changed so that the driver feels uncomfortable feeling because the vehicle behavior is changed from the driver's assumption.